linux-kernel - Re: [PATCH 1/2] x86: Check return values from early

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Message-ID: <Y0bjBP6/Eyg8B25k@zn.tnic>
Date:   Wed, 12 Oct 2022 17:53:40 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Ross Philipson <ross.philipson@...cle.com>
Cc:     linux-kernel@...r.kernel.org, x86@...nel.org,
        dpsmith@...rtussolutions.com, tglx@...utronix.de, mingo@...hat.com,
        hpa@...or.com, luto@...capital.net, dave.hansen@...ux.intel.com,
        kanth.ghatraju@...cle.com, trenchboot-devel@...glegroups.com,
        Jan Kiszka <jan.kiszka@...mens.com>,
        jailhouse-dev@...glegroups.com, xen-devel@...ts.xenproject.org,
        Andrew Cooper <andrew.cooper3@...rix.com>
Subject: Re: [PATCH 1/2] x86: Check return values from early_memremap calls

On Wed, Oct 12, 2022 at 11:13:20AM -0400, Ross Philipson wrote:
> I am already using the pr_* macros in the patches. Are you asking me to do
> something

Yes. You do

pr_X("prefix_string: msg"

while you should set the prefix string and do

pr_X("msg".

As said, grep the tree for examples where pr_fmt() is set.
arch/x86/kernel/cpu/bugs.c is a good example.

> When I was working on the patches I asked Andrew Cooper at Citrix what
> action I should take if any of the calls in the Xen code failed. I
> believe he told me it was basically fatal and that panic() would be
> fine there.

Yes, that should be confirmed by people who know the code and you should
mention in the commit message at least that panicking is the only viable
thing to do in the respective case. If, as Jürgen says, it is actually
better to panic() in those cases, especially if it otherwise would make
debugging harder, then sure, by all means.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette